BIOS - basic input/output system
(bī´ōs) Acronym for basic input/output system, the built-in software that determines what a computer can do without accessing programs from a disk. On personal computers (PCs), the BIOS contains all the code required to control the keyboard, display screen, disk drives, serial communications, and a number of miscellaneous functions.
The ROM BIOS Explained
The BIOS is typically placed in a ROM chip that comes with the computer (it is often called a ROM BIOS). This ensures that the BIOS will always be available and will not be damaged by disk failures. It also makes it possible for a computer to boot itself. Because RAM is faster than ROM, though, many computer manufacturers design systems so that the BIOS is copied from ROM to RAM each time the computer is booted. This is known as shadowing.
Many modern PCs have a flash BIOS, which means that the BIOS has been recorded on a flash memory chip, which can be updated if necessary.
PC BIOS Standardization
The PC BIOS is fairly standardized, so all PCs are similar at this level (although there are different BIOS versions). Additional DOS functions are usually added through software modules. This means you can upgrade to a newer version of DOS without changing the BIOS.
- Watch Datamation's editor James Maguire moderate roundtable discussions with tech experts from companies such as Accenture, Dell, Blue Jeans Network, Microsoft and more »
Learn about each of the five generations of computers and major technology developments that have led to the current devices that we use today. Read More »Small Business Marketing's Greatest Hits
The following compilation of small business marketing tips highlights some of the expert advice published over at Small Business Computing. Read More »13 Best Free Android Apps
From secure messaging to document editing, our top free must-have apps have been rated, reviewed and named the best free Android apps of 2015. Read More »
With cost and security in mind, we look at five cloud storage options that will suit the needs of most home and SMB owners. Read More »Windows 10 Tips for Desktop PC
Five basic tips to help you customize Windows 10 on your desktop PC. Read More »29 Free Android Apps for Cash-Strapped Students
From wacky alarm clocks to lecture hall tools and after class entertainment, these Android apps are a good fit for a student's life and budget. Read More »